DNA replication

Question 1

zygote with an extra chromosome is called

Answer 1

trisomic

Question 2

zygote that is missing a chromosome is called

Answer 2

monosomic

Question 3

aneuploidy

Answer 3

a gamete with an abnormal chromosome number used in fertillization

Question 4

polyploidy

Answer 4

more than 2 complete sets of chromosomes are present (triploidy 3 sets or tetreploidy 4 sets)

Question 5

what are the 4 types of errors that can occur in meiotic division?

Answer 5

deletion (genes are missing), duplication (duplicated fragment reattaches), inversion (broken fragment reattaches backwards) , translocation (broken fragment attaches to a non-homologous chromosome)

Question 6

helicase

Answer 6

enzyme that untwists and seprates the two strands of DNA at the replication fork.

Question 7

single stranded binding protein

Answer 7

binds to seperated strands to stop them from reattaching

Question 8

topoisomerase

Answer 8

swivels and rejoins the DNA strand upsteam of where it is being twisted

Question 9

rna primer is synthesized by

Answer 9

primase

Question 10

DNA polymerase

Answer 10

catalyzes the addition of the new DNA strand by adding ncleotides one by one (DNA polymerase 1 and 3 are most important)

Question 11

what happens when a DNA strand is assembled 3’to 5’?

Answer 11

the strand is lagging, it is synthesized discontinuosly forming small fragments okazaki fragments, DNA ligase then fills in the gaps between the fragments according to DNA template.

Question 12

plasmid

Answer 12

smaller circular DNA in addition to the larger circular DNA found in prokaryotes

Question 13

heterochromatin

Answer 13

half wound chromatin structure